small essay. please correct me

According to the passage, DDT brings more danger than benefits. The lecturer partly agrees with this statement that sometimes DDT is a hazardous poison, but highlights the idea that DDT is more useful, putting forward a few examples.
First of all, the author assures that DDT is harmful to wildlife. Whereas, killing insects can lead to losing flora and fauna. The speaker does not support this argument and states that DDT kills __ insects which supposedly can spread __ diseases to _   plants and animals.

Secondly, the author points out that DDT causes ___human`s diseases and leads to an increase in the death rate. The lecturer gives counterargument to this statement, mentioning the real numbers of conversely decreasing death rate on Sri-Lanka with the start of DDT usage. Moreover, the speaker notices that a small quantity of DDT does not influence significantly the human`s health. Also, nevertheless, DDT is spread or not, it cannot prevent such diseases as malaria.

TOEFL independent writing

The extended family (grandparents, cousins, aunt and uncle) is less important now than it used to be in the past.
Being in a large family is a precious thing that unluckily does not occur to everybody. Many family members argue and do not get on well with each other. Even though this could happen, I personally believe that having a family is now valuable more than ever. I fell this way for two main reasons__ which I will explore in the following essay.
To begin with, many people prefer friends to their family because they claim that they can choose a friend, while they cannot choose a relative. Although it is true, I think that with a family member you can have a strong and true relationship. You usually live with them and you go through many important occasions in your life together. To be more specific, you pass relevant moments together, for example, birthdays, graduation or wedding. In this occasion, you share strong feelings that allow making the relationship much stronger. For instance, when my uncle got ill and was recovering at the hospital, I became very close to my cousin. Indeed, she was really sad and suffered from her father's state of health. I tried to spend time with her to cheer her up and we became good friends.
Secondly, many people state that nowadays you do not need a family anymore because it is hard to stay in touch with them_ since the majority of people go to work abroad. I do not agree with that. Certainly, I have to admit that it is more difficult to keep the relationship at distance, but___ these days there are many ways to remain in contact, for example, with a video call. My personal experience is a compelling example of this. During my high school, I went for a year to study abroad. In the beginning, it was hard to keep in touch with my family, but I always managed to have a call with any of them once in a while. I was very happy to discover that even if we spent less time together, our relationship would have grown stronger than ever. In fact, when I called them, I knew that I did not have much __ time to do it. As a result, I tried to enjoy the most and take advantage of every call as its best.
In conclusion, I strongly believe that family is essential in this age. This is because the relationship is stronger than the one with your friends, and because with the internet it is easier to stay in contact with them.

Is there any mistake in my five sentences?

Deforestation was the principal cause for unproductive land in Europe, causing damage to 9.8% of the land, compared to 1.7% in Oceania and 0.2% in North America respectively

Deforestation was the principal cause of __ unproductive land in Europe, causing damage to 9.8% of the land, while the proportions of land degradation in the other two countries were significantly lower.

Deforestation was the principal cause of __ unproductive land in Europe, causing damage to 9.8% of land, meanwhile the proportions of land degradation in the other two countries were significantly lower.

Deforestation was the principal cause of __ unproductive land in Europe, causing damage to 9.8% of land, while the figures for the other two countries were significantly lower.

Deforestation was the principal cause of the unproductive land in Europe, causing damage to 9.8% of the land, while the figures for the other two countries were significantly lower.

My comments:  a good structure. Just be sure that it's "cause of.." and put "while/meanwhile" instead of "but". Some further work with articles is required. All the rest is great!

Introvert? Part one

If you wonder if you are an introvert or I if you are interested in how an introvert acts, please watch some Ted Talks Conferences on that subject. There are a few, but they are interesting.
The first one I watched was by Susan Cain. To sum up: a third to a half of the population in the world belongs to  introverts. Introverts like and need to spend some time on their own, but not necessarily alone. To read a book near the other members of your family could be an example of a social activity for introverts. Nobody is one hundred percent introvert or extravert, every single person is a mix of both tendencies.
Everybody can contribute and will have to contribute to find solutions for all the huge problems our societies face, and for that everybody has to evolve in a context which is favourable to think, and to create or to propose solutions. And for that introverted people need more privacy, more autonomy, and sometimes more solitude. But nowadays our societies promote open space offices, collaborating for everything, even at school, where a good student has to be an extravert.
The conclusion : the world needs introverts and extraverts to face challenges, so we all have to make sure that introverts can also find good conditions at school, at work, to be themselves, to think, to create and then afterwards to share with others their contribution.

The wealth's pillars

I am pretty sure that each of us is capable of becoming the person we want to be. But this requires something more than a powerful determination of just doing. One of the most awesome human qualities is the ability to change with time and constantly improve oneself. Saying that it's not possible to transform oneself, or imperfections will be always there, just because "we were born like this" is a mediocre saying.